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Sanada, Yukihisa; Abe, Tomohisa; Sasaki, Miyuki; Kanno, Marina*; Yamada, Tsutomu*; Nakasone, Takamasa*; Miyazaki, Nobuyuki*; Oshikiri, Keisuke*; Watabe, Hiroshi*
Journal of Nuclear Science and Technology, 10 Pages, 2023/00
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)The "treated water" from which the main radioactive materials were removed contains tritium, and stakeholders in Japan have been debating how to treat it. The amount of treated water stored in the facility has reached its limit, and the Japanese government has decided that the treatment method will be to discharge the water into the ocean by FY 2023 (FY: Fiscal Year). The present research developed a simple and practical tritium monitor for the Fukushima Daiichi Nuclear Power Station (FDNPS) tritiated water release. A simple and practical tritium monitor was developed for FDNPS tritiated water release based on thin plastic scintillator sheets. The developed devices were calibrated using standard tritium solutions and a method for calculating the minimum detectable activity. Fifteen 0.25 mm-thick scintillators can be placed in the 0.26 L flow cell where the sample water is fed, yielding an active surface area of 3,200 mm
. The efficiency of tritiated water with full water is 0.000035 cps Bq
. The minimum detectable activity under simple shielding conditions was 7,800 Bq L (Measurement time was 3,600 s).
Sanada, Yukihisa; Miyamoto, Kenji*; Momma, Hiroyasu*; Miyazaki, Nobuyuki*; Nakasone, Takamasa*; Tahara, Junichiro*; Baba, Shoichiro*; Furuyama, Hiroki*
Marine Technology Society Journal, 55(5), p.222 - 230, 2021/09
Large quantities of volatile radionuclides were released into the atmosphere following the Fukushima Daiichi Nuclear Power Station (FDNPS) accident in March 2011. To evaluate their effect on aquatic organisms and radiocesium behavior in the environment, the monitoring of radioactive cesium in the waterbed soil is important. We developed a dedicated radiation survey device that can both directly measure and collect some sediment samples. A comprehensive test was conducted using this device, which was installed in an unmanned surface vehicle at Fukushima offshore contaminated by radiocesium that resulted from the FDNPS accident. Consequently, the effectiveness of this device was confirmed because the measurement results of the sediment-core sample and in-situ radiation survey results show a good correlation. A successful application of this device in the time of post-nuclear facility accident is expected.
Sasaki, Miyuki; Yamada, Tsutomu*; Nakasone, Takamasa*; Sanada, Yukihisa
no journal, ,
no abstracts in English
(Ce) detector used for estimating radiocesium distribution in soilMalins, A.; Ochi, Kotaro; Nakasone, Takamasa*; Yamada, Tsutomu*; Machida, Masahiko; Kurikami, Hiroshi; Saito, Kimiaki; Sanada, Yukihisa
no journal, ,
Here we report PHITS Monte Carlo simulations of a LaBr(Ce) gamma spectroscopy system used in unmanned helicopter radiation surveys in Fukushima Prefecture. The simulated spectra were verified against measurements taken under controlled laboratory conditions. Simulations were used to characterize the peak-to-Compton method for estimating the vertical distribution of radiocesium in soil from airborne surveys.
(Ce) detector for estimating radiocesium distribution in soilOchi, Kotaro; Malins, A.; Ishida, Mutsushi*; Yamada, Tsutomu*; Nakasone, Takamasa*; Sanada, Yukihisa
no journal, ,
no abstracts in English
